In 1934 the staff of the Yokosuka Navy Arsenal turned their hand to the design of a twin-engined flying-boat, the Yokosuka H5Y powered by two 895kW Mitsubishi Shinten 21 radial engines. Although built to a total of 20 during 1936-40 as the Navy Type 99 Flying-Boat, its performance was disappointing and, consequently, was deployed only on second-line duties.
H5Y1 Engine: 2 x Mitsubishi Shinten-21, 895kW Max take-off weight: 12500 kg / 27558 lb Wingspan: 31.57 m / 104 ft 7 in Length: 20.52 m / 67 ft 4 in Max. speed: 305 km/h / 190 mph Ceiling: 5200 m / 17050 ft Range: 4700 km / 2921 miles Crew: 6 Armament: 3 x 7.9mm machine-guns Bombload: 500kg